The present invention relates to data processing, and particularly, to text retrieval and index.
Studies have shown that the volume of information will be doubling every two years. How to use these information resources and discover the value of them has become a key issue. Search by means of indexes is one of the major uses.
An existing technique for this use is inverted index. It is an index data structure storing a mapping from content, such as words or numbers, to its locations in a database file or in a document or a set of documents. By means of inverted index, fast full text searches can be performed. In general, an inverted index may include a plurality of terms (e.g., words or numbers) and a same number of posting lists each of which records the location related information of a term in one or more documents. As the volume of information grows, it is desirable to have more efficient techniques for index and text retrieval.